Armature for magnetos.



B. AMES.

ARMATURE FOR MAGNETOS.

APPLICATION FILE D MAR. 28. 1914.

Patent-ed Sept. 7, 1915.

2 SHEETS-SHEETI.

B. AMES.

ARMATURE FOR MAGNETOS.

APPLICATION FILED MAR. 28. 1914.

1,153,006, Patented Sept. 7, 1915.

f uumm 2 SHEE TSSHEE1 2.

BUTLER AMES, OF LOWELL, MASSACHUSETTS.-

FFICE.

' ARMATURE FOR MAGNETOS.

To all whom it may concern Be it known that I, BUTLER Arms,- a citizen of the United States, residing at Lowell, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Armatures for Magnetos, of which the following is a specification, reference beinghad therein to the accompanyingdrawings.

The principal objects of my invention are To increase the efliciency of a-magneto. To reduce the cost of manufacture. To design the armature so that it may be made up of separate and independent pole pieces, core, primary and secondary windings, and insulation that may be easily and quickly assembled, or taken down in whole or in part, for

the purpose, say, of replacing a defective part, as insulation, coil, or core. To perfect the insulation of the primary coil from the secondary coil. To increase the number of turns of wire on the core of the armature;

and, further, yet increase the number of lines of magnetic force.

Heretofore, in order to avoid objectionable eddy currents, around the ends of the core of an armature, the core has been provided centrally with longitudinal metal laminations, all parts of the armature being bound together as by suitable bolts. By this construction the cross sectional area of the core was for strength, necessarily great, the number of turns of wire around the core was limited and consequently the electrical capacity of the machine. Further, the armature windings and the insulation had to be wound directly upon the core of the armature, for the pole pieces prevented them from being slipped onto the core; so that if, for example, the primary coil became defective, the secondary had to be unwound or cut off; and then the primary subjected to similar treatment. To complete the repair, the armature had to be rewound in the same manner, as when originally made.

Now by means of one feature of my invention, all of the parts of the complete armature, are madev independent of each other, and in case of need, permit any one or more of. them to be duplicated, or repaired; a construction which can be quickly. and easily taken down or assembled. For example, if necessary, one of the pole pieces may be removed from the core, so that the second ary coil may he slid 0d from the primer, and the primary frcm the core, and should,

Specification of letters Patent.

- Application filed March 28, 1914. Serial No. 827,872.

' Patented Sept. '2. 1915.

say,-the latter be defective, a new primary coil, wound in any suitable form, may be sllpped onto the core; the old secondary, restored to normal position; and the detached pole piece, put back in proper relation to the core.

Another feature resides in an air gap cut 3 from one edge of a pole piece to a point opposite the end of the core. This feature does away with laminations of the core, and prevents the objectionable eddy currents above mentioned.

Still another feature is found in a duplication of removable cores in one armature, whereb for a given pole piece, there may be utilized, a greater number of lines of magnetic force, and a greater number of turns of wire than could be heretofore; that is, by using two or more cores, then each may be of less diameter and hence together have thereon, more turns of wire, than if only one core of larger diameter with fewer turns, were employed.

The apparatus whereby the other objects of my invention may be attained will be explained hereinafter. v

In the drawings illustrating the principle of my invention and the best mode now known to me of embodying the same in operative structure, Figure l is an elevation of an armature containing my invention; 1 is an end view thereof; Fig. 2 is an elevation, broken away, showing features of my invention in longitudinal section; Fig. 3 .is a perspective view of part of my invention in elevation; Fig. 4 is a similar view of a fragment thereof; Fig. 5 is a plan; Fig. 6 is a perspective view of a piece of insulation used in separating the. primary from the secondary winding; Fig. 7 is a like view of insulation covering the secondary winding and serving also to insulate the primary from the secondary winding; Fig. 8 shows all of the features of my invention, either in core 2, Figs. 2 and 3, is made up of a cylinder of fine wires surrounded by a winding of paper-3. Each pole piece 1, Figs. 3 and 4, comprises a segmental portion of a cylinder, the diameter of which is that of the armature; and has a hole or seat 41, Fig. 2, for the free end of the core, formed in the inside face of the pole pieces, the longitudinal axis of the core being centrally located between the outside edges of the pole piece, and in a plane at right angles to the inside face of'the pole piece. An air gap 5, Figs. 3, 4 and 5, is formed in the pole piece by cutting a slot from the edge thereof to a line in the pole piece, theoretically containing the longitudinal axis of the core. A second pole piece similar in every way to the first, is likewise mounted on the opposite end of the core, and in parallelism with the first ole piece, as clearly appears in Fig. 8. Each end of each pole piece has threaded screw holes 6 and a lock and centering pin 7, whereby, with screws 8, Fig. 1", and suitable holes therefor, the pole pieces may, in the manner later to be pointed out, become fixed to the armature end pieces.

The core and slotted pole pieces comprising the first feature of my invention, may obviously be easily knocked down or assembled. A primary winding 9 and a secondary winding 10, both previously made, may be slipped onto this core in substantially the same manner as are such windings, u on the core of the ordinary spark coil.

owever, in thus supplying this core with these windings, which, it must be remembered, this demountable structure permits, I make use of another feature of my invention, namely, improved means for insulating the primary winding from the high tension secondary winding. These comprise two separate pieces of suitable insulation 11, 11, Figs. 2 and 6, each, cylindrical in form, and having a thin collar 12 near its end portion; and beingv of such length that when the two pieces are slipped over the primary winding 9 and their inner ends abut, the primarywinding is completely covered by the insulation, the outerend portions of which fit closely to the under surfaces of the ole pieces, as clearly appears in Fig. 2. till further insulation 13, Figs. 1, 2 and 7, is provided to protect the secondary winding 10, by completely covering it; and also to give additional insulation between the primary and the secondary winding, that makes it practically impossible for any electricity to. travel from the secondary winding to the primary winding. This insulation 13 is saucer shaped with a hole 14 through its bottom, corresponding in diameter to the outside diameter of the cylindrical insulation 11; while the inside diameter of its base equals that of the collar 12 of the cylinder. Fig. 8 shows all of the elements of the armaturearranged for the orderly assemblage of the complete armature as seen in Fig. 2. To set up these parts, the core 2 is moved up into its seat 4 in the pole piece 1; next,

the cup insulation 13 goes on, until it abuts the under side of the pole piece; a primary winding 9 is then slipped onto the core, one end portion of it passing throu h the hole 14 in the bottom of cup insulation 13, and into contact with the inside of the pole piece; next, push a section of cylindrical insulation 11 over the primary winding 9 until the outside of the collar 12 engages the inside base of the cup insulation 13, the free outside portion of the cylindrical insulation, passing through and closely fitting the hole in the bottom of the cup insulation and into contact with the inside of the pole piece. Now, slip the secondary winding 10 over the cylindrical insulation 11; then insert the second cylindrical insulation 11 into the space between the secondary and the primary windings, so as to be in contact with the inner edge portion of the first cylindrical insulation, the inside of the collar 12 of the second insulation engaging the exposed end portion of the secondary winding. ext, the outside cup insulation 13 is pressed onto the cylindrical insulation until its bottom engages the outside of the collar of said insulation; the free end portion of the latter insulation extending through the bottom of the outside cup insulation. Finally, the second pole piece 1 is fitted upon the free end portion of the core 2. The fit between the end portions of the pole piece and the core being tight, all of the above mentioned parts are sufiiciently secured together to permit them to be assembled with the end pieces A, B, of the armature, by causing the suitable screw holes 6 and lock-pin 7 in the end pieces to register with those in the pole pieces, and bringing the parts together by means of screws 8.

It will be plain from what has been said, that the'various elements of this armature may be made in great numbers, in duplicate,

It is to be understood that this invention does not contemplate any particular arrangement of circuits, this being left to the discretion of the manufacturer. It is also obvious that the armature may have more than one core, should it be thought desirable. As shown in Figs. 9, 10 and 11, the armature has a duplication of the core, already described. The great advantage flowing from it that while the diameter of each core maybe" smaller than any of the cores heretofore employed, yet for a given pole piece their total cross sectional area 1s greater and many more turns of wire may be used around each of its two separate cores than could be used around one of the old cores of the required cross sectional area.

Desiring to protect my invention in the broadest manner legally possible, what I claim is An armature having a core; and two pole pieces; one of which is removably secured thereto; a primary coil removably slipped thereon; a secondary coil removably mounted over said primary coil; two collared tubes of insulation removably mounted upon said primary coil, and abutting each other and separating said primary and secondary coils; insulating material covering the space 16 thereby completely insulating the primary 20 coil from the secondary coil.

In testimonywhereof I hereunto aifix my signature in the presence of two witnesses.

BUTLER AMES.

Witnesses JOSEPH A. LEGARE, JOSEPH C. CooLoMBE. 

